40C3: tours, schedule data, tour map and calendar entries

- tour-map shortcode: Leaflet map of the tour locations with routes from the
  Congress, from the map/tours sections of data/schedule/<event>.yaml; Leaflet
  and the OSMIC, Maki and Temaki icon sets vendored; 39C3 uMap data converted.
- calendar shortcode: per tour date, a pill with an .ics download (iCalendar)
  and a Google Calendar link; Font Awesome Free vendored, fa-icon partial.
- README sections for the calendar and tour map shortcodes and the map data.

assets/vendor/icons/temaki/bollard_row.svg

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 15 15">
+  <path d="M6 4C6 2 9 2 9 4C9 4.5 6 4.5 6 4zM6 4.5C6 4 6 11.5 6 12C6 12.5 9 12.5 9 12C9 11.5 9 4 9 4.5C9 5 6 5 6 4.5z"/>
+  <path d="M1.5 4C1.5 2 4.5 2 4.5 4C4.5 4.5 1.5 4.5 1.5 4zM1.5 4.5C1.5 4 1.5 11.5 1.5 12C1.5 12.5 4.5 12.5 4.5 12C4.5 11.5 4.5 4 4.5 4.5C4.5 5 1.5 5 1.5 4.5z"/>
+  <path d="M10.5 4C10.5 2 13.5 2 13.5 4C13.5 4.5 10.5 4.5 10.5 4zM10.5 4.5C10.5 4 10.5 11.5 10.5 12C10.5 12.5 13.5 12.5 13.5 12C13.5 11.5 13.5 4 13.5 4.5C13.5 5 10.5 5 10.5 4.5z"/>
+</svg>